Two percent of the US workforce has a compensable low back pain (LBP) injury each year with an estimated total[unreadable] annual cost exceeding $20 billion. Approximately 40% of those who report an occurrence of LBP on the job associate[unreadable] that injury with overexertion while lifting objects. There is a significant need for increased understanding of the[unreadable] mechanisms of lifting tasks in order to improve programs for injury reduction.[unreadable] Lifting injuries to the low back occur when mechanical stress exceeds the tolerance limits of the involved tissues[unreadable] thereby producing excessive motion between spinal segments. The ability to adequately stabilize the segments of the[unreadable] lumbar spine to prevent this excessive motion via coordinated muscular control is a common goal in low back exercise[unreadable] programs. As the musculature of the abdominal cavity contracts around the abdominal contents, intra-abdominal[unreadable] pressure (IAP) increases and converts the abdomen into a "rigid cylinder" that has an increased stability compared to[unreadable] the multi-segmented ligamentous spine. Several studies suggest that increases in IAP increase lumbar stability. As the[unreadable] diaphragm forms the roof of the abdominal cavity, breath control can contribute to both respiration and IAP production.[unreadable] Breath control has been shown to be directly related to IAP production as well as to direct in-vivo measures of lumbar[unreadable] stability. The importance of coordination of the respiratory and motor systems during lifting tasks to achieve sufficient[unreadable] lumbar stability has been suggested by multiple authors, although there has been almost no study of natural breath[unreadable] control during lifting tasks exploring this issue. Increased understanding of the normal coordinative patterns of[unreadable] respiratory and motor systems may allow improved training methods in exercise programs for lumbar stability and[unreadable] contribute to both prevention and rehabilitation of low back pain due to lumbar instability.[unreadable] Specific Aim 1: Develop novel methods of data collection and analysis of breath control patterns during lifting tasks[unreadable] that can be used to determine if the timing, magnitude and direction of these patterns demonstrate theoretical support[unreadable] for lumbar stability at critical moments of mechanical challenge.[unreadable] Specific Aim 2: Determine the effects of different levels of challenge to lumbar stability (e.g., load, vertical height,[unreadable] horizontal distance) during lifting tasks on the breath control patterns in healthy normal subjects.[unreadable] Specific Aims 3: Determine the effects of different levels of challenge to lumbar stability (e.g., load, vertical height,[unreadable] horizontal distance) during lifting tasks on the breath control patterns in patients with intermittent mechanical low back[unreadable] pain.[unreadable] Specific Aim 4: Determine if the patterns of breath control during lifting tasks used by patients with intermittent[unreadable] mechanical low back pain differs when compared to breath patterns of normal subjects.[unreadable] The research we propose will provide the first complete descriptions of breath control during lifting tasks and will be[unreadable] the first to determine if significant differences in respiratory and motor system coordination exist between subjects with[unreadable] and without low back pain. This pilot project data will provide estimates of effect size that can be used in the design of[unreadable] larger related studies. This research has the potential to provide meaningful new information in the area of lifting tasks[unreadable] and low back pain and have direct applications in the area of lumbar stability training to prevent or reduce low back pain.[unreadable]